On 12/01/2016 13:57, Pavel Fedin wrote:
> Hello!
>>> I might be missing something obvious here but, aside from having memory
>> SHARED which most DPDK apps using hugepages will have anyway, what is
>> the backward compatibility issues that you see here?
> Heh, sorry once again for confusing. Indeed, with hugepages we always get MAP_SHARED. I missed that. So, we indeed need
> --shared-mem only in addition to --no-huge.
>> Backwards compatibility issue is stated in the description of PATCH 1/4:
> --- cut ---
> b. possible ABI break, originally, --no-huge uses anonymous memory
> instead of file-backed way to create memory.
> --- cut ---
> The patch unconditionally changes that to SHARED. That's all.
I should read more carefully!
Sorry about that, I thought you were the one with the ABI concerns.
Regarding ABI, I don't think there is any ABI issue with the change, we
just have our memory file-backed and SHARED but we do that when using
hugepages so I don't think it would be a huge issue.
But if folks have concerns about it, we could always keep old behavior
by default and, as you suggest, introduce another option for changing
the flag.
Sergio
> Kind regards,
> Pavel Fedin
> Senior Engineer
> Samsung Electronics Research center Russia
>>